For a client device that acts as an intermediary device between a media device (e.g., a television set top box) and an output device (e.g., a television display), it is desirable for an application executing on the client device to obtain video streams from media devices that are accessible to the client device so that these video streams may be displayed on the output device. However, during development of the application, a developer of the application for the client device does not know which media devices in a plurality of media devices will be coupled to the client device. Furthermore, each media device that is coupled to the client device may have a different protocols and addressing mechanisms in which video streams that are available on the media device are obtained. Including these protocols and addressing mechanisms for all possible media devices in the application during development of the application is burdensome and impractical for the developer of the application.